The invention concerns an ultrasonic atomizer, which is intended for an inhalation treatment apparatus for persons suffering from respiratory diseases, said ultrasonic atomizer comprising an atomizer device provided with a drug container as well as an ultrasonic oscillator connected to the container, preferably an oscillating crystal, and said atomizer device being provided with a duct passing into the patient, advantageously a mouth piece and an air-inlet duct, and said atomizer device comprising a pressure detector directly connected to the atomizer device or a duct that is connected to the atomizer device and passes to the pressure detector and transmits the pressure of the breathing air, whereat the pressure detector detects the changes in pressure resulting from inhalation or exhalation of the patient, whereby, starting from the beginning of the inhalation stage, atomizing can be switched on by the apparatus, and said ultrasonic atomizer comprising a regulating device connected to the atomizer device, by means of which regulating device the operation of the ultrasonic oscillator is regulated.
Water or drug mist that is used in respiration treatment can also be produced by means of ultrasonic oscillations. By means of intensive oscillation, a field of waves is produced on the surface of liquid, in which the velocity of the liquid particles in the waves becomes so high that it surpasses the effects of gravity and of surface tension forces, and small particles are detached from the liquid surface into the air. The drop size is determined by the properties of the liquid and by the ultrasonic frequency used in the ultrasonic oscillator. Most commonly, the ultrasonic frequency in treatment atomizers is of an order of 1 to 2 MHz. In such a case the drop size of water mist becomes 2 to 5 .mu.m. The atomizing capacity of the ultrasonic atomizer depends on the size of the oscillating crystal and on the magnitude of the electric power supplied to the crystal. For example, with a crystal of a diameter of about 15 mm and with a power of about 12 W, the water atomizing capacity that is obtained is about 250 ml/h.
A drawback of the prior art ultrasonic atomizers is the short service life of the oscillator crystal. Nor has a precise adjustment of the atomizing been possible in the prior art ultrasonic atomizers. Thus, it would be an improvement if the atomizing time could be adjusted so that it is advantageous in view of the treatment of the patient. Therefore, an apparatus would be advantageous in which the optimal atomizing time can be adjusted individually for each patient. In view of the short service life of the apparatus, it would also be advantageous to be able to form an ultrasonic atomizer in which it is possible to increase the service life of the ultrasonic crystal considerably, without deterioration of the treatment results.